Syringe



Sept- 4, 1934. o. o. R. SCHWIDETZKY 1,972,167

SYRINGE Filed Nov. i932 WITNESS INVENTOR 050/? 0. R. ic/m/mzrzxr A TTORNE 5 Patented Sept. 4, 1934 UNITED STATES" PATENT OFFICE SYRINGE.

Oscar 0. R. Schwidetzky, Hasbrouck Heights, N. .L, assignor to Becton Dickinson & C04 Rutherford, N. .L, a corporation of New'Jersey Application November 26, 1932, Serial No. 644,432,

11 Claims. (01. 12s 2s1) The invention relates to syringes of the type which comprises a compressible air bulb and a cylinder or barrel for receiving fluids, the bulb being associated with the barrel by frictional con tact with an extension of the bulb. Such syringes usually comprise aglass barrel whose capacity is materially inexcess of that of the-airspace within the bulb while the air channel or channels through which communication is established .between the barrel and the bulb are of such limited dimensions as to prevent the liquid within the' barrel from flowing'into the bulb when the barrel is held with the nozzle pointing upward; Syringes of this character are and have beenin wide use for many years but they have certain defects,

' for' example-that the bulbs cannot be satisfactends through the neck of the bulb and which is purposely kept small for the reason above stated.

torily flushed, cleaned, and drained, which have thus far not been satisfactorily remedied. It'is the object of the present invention to remedy such defects and to improvethe syringe structurally.

In existing bulbs, due to their structural character, the interior of the bulbs'can be drained only by'admitting fluid into and ejecting fluid 'out of the-relatively small airpassage which ex- Attempts at flushing, cleaning, and draining of 'the bulbs through this small channel have never been satisfactory. In studying the cause I have found that in the vulcanization process employed in the manufacture of the bulbs the interior surface of the neck portion of the bulb is'not smooth or even but is usually-full of crevices within which undesirable fluids and solids are capable of lodging without being ejectable therefrom by the flushing or draining operation; Fine powder appearing on the interior of the bulb as a result of the vulcanizing process settles in the crevices referred to and as it cannot well be flushed out, in time finds its way into the medicinal liquids contained in the barrel and introduces an undesirable impurity. Perfect'flushing could, of course, be attained by greatly enlarging the air channel but this in turn would defeat the principle of the syringe that the air channel must be'kept so small that when the syringe is held barrel up or when laid on a flat surface, fluidwill not flow into the bulb through the channel. I have found that the unsatisfactory conditions referred to can be completelyremedied by establishinga relatively large drainage passage or passages through the sides of the neck of the bulb in the region of the inner wall of the forward part of said neck and having the neck of sufi'icient length that when associated with the barrel the large openingsof the large passages will lie between two portions of the neck which are in continuous frictional engagement with theinner wall of the barrel above and below the said openings. In tl'iisway'whend the barrel and the bulb are assembled there will be established; notwithstanding the presence of affected by thepres'ence of these large openings.

In the use of the 'syringe all of the airused for drawing in or expelling fluid into or from theZ barrel passes whollythrough the small channel. When, however, the 'bulbis detachedv from the barrel an'dflushed, theflushing fluid'rush'es in through the large, lateral channels, practically 1 none of 'it entering through the'small channel31 and the forces developed in the flushing operation unseat all impurities since the liquidin rushing in the larger channels directly reaches all of the crevices and irregularities of that part'of-the'inte'rior of the bulb where those'irregularitie's usu-E- ally appear. When the flushing liquid is ejected from the bulb it flows out practically entirely through the large passages and sweeps away all impurities contained in the interior of the bulb and then as the bulb finally drains, allows every-e thing which was inside of the bulb to be drained away. If," for "example, a certain medicament was usedin the syringefor one purpose and a part of it had slipped into the interior of the bulb through the small aperture and the syringe wasgSO next to be used with an entirely different medicament, it ispossible withthe new arrangement to thoroughly remove all traces of the first medicament from the interior of the bulb before the syringe is reassembled for the use of thecgie second medicament.- There is no chanceof any intermixture as between remnants of the first medicament and the 'second'medicament.

In 'order'to' strengthen the neck 'of' the bulb and also to enable me to reducethe size of theii i smaller passag'eandyet preserve a reliable functioning thereof, I provide a metal tube to constitute the smaller passage and preferably so locate the inner end of said tubelthat it'willlie M approximatelyflush with the side of' the larger channels, in this way assuring completedrainage when the bulb is flushed and preventing the collection of'a liquid accumulationaround the inner endof the metaltube. I

The invention isillustrated'in the accompanya $1 ber bulb, the air space in which is preferably less than the liquid space in the barrel A. The :brulb is associated with an integralneck N.ha.ving av forward section N, saidse'ction Nlbeingrjprefer-a tional type having a fluid inlet atC, and bulband bulb-neck-engaging portions D. B is a.r.-i-1bbarrel. This in turn reduces the passages to less than minimum and brings about a condition where the syringe does not function as perfectly as it should. By using rigid tubes T to define the passages, the minimum condition described will be defined by the passages through the tubes T which, having-rigid walls, will not be compressed ably thicker than the .walls ofmthe bulb-.-. itsel f and the walls of the neck N. This thickening of the section N results i'rr-increa'sed=-resistance to transverse compression and therefore participates in insuring a liquid-tight fit between the exterior of thersectionNflland the wall of \the. glass ebarrelvwith'which it is in :compressing. contact :vsurface N 'ofv the.neck-section N and the-.-in-ner lraround :its. entire periphery.

-sa-Atxthelrrear. of Ni; are situatedi1the=usualrsur-i trace"irregularities;. crevices andrspock'ets vindigccated at E..---Relativ,ely large channels? are pro-1.

nvided laterally through the walls of the-neck; N

eand extend: to 'zthe region occupied byi the ir-: -:.--.reg;ularities -.There;.-may=wbe 1 oneorw more 1 of 1 barrel-are assembledthe iargeapertures Emmi-i105 --a3(y.'such.passages.F. ;I;-preferably use-two;extending :aeach' angularly: towardthe longitudinal *a-xial ---center. line of the bulb: and neck and forming each ,sanobtuseagngle with reference: to .the; lines drawn oralteredby reason of compression Offzthfi rubber portions of the neck as the neck is inserted in the barrel. One object of the metal tubes T, therefore, is to maintain a fixed diameter of the air passages through which communication is established between the air of the bulb and the barrel of the syringewhich in turn makes it pos- 's'ible. "after. adopting the preferred minimum diameter ofitheapassage through T to maintain that diameter in all future manipulations of the syringe'or-its-=parts.

.The neck N inclusive of its section N is of such length that when assembled with the barrel A as shown inFig. I,- there willcbe a continuous frictionalr'engagementbetween the entire. exterior wall of the barrel A forward of the large apertures F and that there will :alsobe a. continuous. 19c frictional engagement.- -between the entire exterior-surface-Ni of the-:neck section N and the t inner 1 wall of the barrel A rearward' ofrthe'rlarge aperturesF, .In this -way-when the bulbzand completely; sealed: against access therethrough! of liquid or passage therethrough of air saidsealed ;condition persisting-throughout the :use i of the iscentrally through \the ;;apertures F- and the. lon-;

435:.gitudinal axial:line:drawn-from the center of--.the

.xbulb toward; the. neck. A rigid .tube T, preferi. Fably'. of corrosion-resistant material or surfaced 'iwith :such material; of :small: or minute calibre,

is :forced' throughani opening adapted to receive Mocsuch a tube-:in the neck .section- N, *beingwposi- .rtioned: in: andzextending through the end wall N nofxthe r-neck: intontheinterior of-.the: bulb and 45 N. 5 through which :the :-tube T extends. wTheatube locatedanywherewith respect: to the face oflthe :f-nels" F (Fig: 3) terminating" practically flush Wallv ofizthez' passage F nearest the. interior. of :the

syringe even when the bulb iS fl IH'Y. compressed: in line withthe apertures F.

. e m r Thetube T. may -be.-loc;a-tedtinaanymther posi- {ti'onthan that shown provided itsi interior orifice is in :communication. with: the air-: contained; in the bulb but it is. preferred tolocate thertubeT at- :t-he-- point .-shown-.-for. 2-the reasons rexplaiinedll There may be several tubes T provided theireaggregate transverse: i areais suflicientlyr'snml'l to :abeing: held' inplacew-by r frictional engagement nwithvther walls :of the;.aperture:in?the end .wall syringe containing-fluid isrheldnozzleun'i It'wvill be apparent from the foregoing: description thalfinll Te may be angularly: or otherwise: inserted and be prevent: material leakage into :the: bulb when =-the thefsyringe of r Fig. *1 will: function in isuch away that: the..-large--pas sage Frmay -be-.-regarded..-as sealed. Should liquid fromthecba-rrel A-;be :ac- :cidentally rdrawrr into-thehulb B, -asr forxexample when thepsyringe -is-.held bulb down andctherbulbcfls is then compressed; and the; pressure released; all

rmvitlnthewall'F: of the channels F; Fiebeing the r-slaarrel. irThe vminute :ors reducedwcharacterr. of

5255 :ltheasmallaaperture through the-tube T is-il-lustratedinvFig. 2 cfromawh-ich it -will.be; :apparent .i (that. the: aperture. is: so"v minute as. to reduce to a nminimurrrv :the-.-pcssibility; oi leakage; of fluid into z'thezbulbxthrongli such passage under; any condicbo tions ofzzusefi The preferredpdimensions; of...the slarge passage F ceases -to-be sealed. nd the- .bulb31-35 can be sthoroughly, completely, and --..reli-ably vrliameter: or diameters; of. the :passage or.- passages rmvhichrestablish :communication .-between-.-the2i-nterior ofthe'air lbulb Band the barrel A--ar.eisuch .saswtoarepresent: minimum requirementsvwittr re- --through zthe passage-or passages into the syringe barrel. The selectioni'of 'these minimum dimensStatedzminimumdiameters: have-rubber walls as ehas'zthux f arz'beennt-he; practice; the: passages :be-

come reduced in sizewhenctheeneck:ofstheibulb 1 is forcedaintoi:thes-larger'rendt Dzofasthe syringe gage through the ztube T.

such liquid is ejectable from the; interior of the i bulb notwithstandingwhepresence. of thez pockets and irregularities E by l merely inverting (the syringe and :compressingtherbulb, r-sinceatlsuch liq-e320 uid :.willon such? inversion; :collect in the passages Frfrom which the liquid will find outlet andrdrain- When the bulb is-detached fromthewbarrel .the

flushed out and-drainedthrough thoseepassages F. arThesez passages Febeing large with respect to i the tube .T, the flushing or. cleanings liquid will 2 65 'spect to' the proper expulsion ofz'airnfromzthebulb practic'ally all enter. -through.-theepassages F end ng will flush-and drain out. through thehpassages-F,

any. liquid which might. accumulate in T. being meadily forced out by closing thapassages F=with the finger-s and? pressing. thebulb.

It will be observeclzinFig. 3 that the exterioral fi of ,Itheneck N at .theportion-N is slightly tapered.

- This-feature enables the-.neckto. be...very. readily inserted inthe neck -receiving end. of. the barrel A. The taper: is so.slight;.hoxvever ,..as nottoin- -terfere withfthe effectuating oiaclosefit between 31:50

the wider portions of the sections N and the inner wall of the barrel forward of the large apertures F. The degree of compression of the neck sections N and Nfiwhen inserted in the barrel and making a continuous circumferential frictional contact with the inner'wall of the barrel is usually such as to give a slightly oval configuration to the large apertures F in a direction longitudi a-lly 0f the barrel, is "an indication of the fact that the proper compression on the neck of f the bulb within the barrel has been achieved and also that the wall thicknesses of the neck portion of the bulb are properly dimensioned to prevent longitudinal compression of the neck and incidentally thereby preventing creases or wrinkles from forming in the sections N and N and rendering impossible the passage of air or liquid between the outer walls of these sections and the inner wall of the barrel such as would be the case if the walls were so insuificiently compressed transversely or so thin as to prevent the orifices of the apertures F to retain their round form or to become oval transversely of the barrel when the neck is inserted in the barrel. In some cases it may be desirable to use rigid tubular elements, of material similar to that used for the tubes T, to line the large apertures F, in which case the said tubular reinforcing members should be so associated with the neck of the bulb as not to interfere with the cross-wise compressibility of the bulb or the sealing effect of the parts N and N of the bulb when the bulb is in place as shown in Fig. 1 of the drawings.

It is apparent that numerous modifications may be made without departing from the scope of the invention as covered by the appended claims whose purpose it is to include and embrace any such modifications or equivalents.

I claim:

1. A syringe comprising a barrel provided at oneend with a nozzle and at its opposite end with an inner surface adapted to frictionally engage the neck of a bulb, a. compressible bulb having an end wall and a neck adapted exteriorly thereof to frictionally engage said inner surface of said barrel, one or more relatively large flushing passages extending laterally through the neck, the outer open end of said passage or passages being positioned between regions where there is complete and continuous frictional contact between the neck and the barrel and a relatively minute air passage or passages extending through the end wall of the bulb between the interior of the barrel and the interior of the bulb.

2. A syringe such asset forth in claim 1 in which the relatively large flushing channel or channels extend laterally through the neck across the interior face of the end wall of the bulb.

3. A syringe such as set forth in claim 1 in which the relatively large flushing channel or channels extend laterally through the neck across the interior face of the end wall of the bulb and in a direction to form an obtuse angle with respect to the longitudinal axis of the bulb and neck.

4. A syringe such as set forth in claim 1 in which the minute air passage or passages come prise a rigid tube or tubes extending through the face of the end wall of the bulb into communication with the interior of the bulb.

5. A syringe such as set forth in claim 1 in which the minute air passage or passages comprise a rigid tube or tubes of corrosion-resisting metal extending through the face ofthe end wall. of the bulb into communication with the interior of the bulb. v

6.. A syringe such as set forth in claim ,1 in:

.which the minute air passage or passages comprise a rigid tube or tubes of corrosion-resisting metal extending through the face of the end wall of the bulb into communication with the interior of the bulb and terminate approximately flush with that face of the wall of a flushing channel which is closest to the interior of the barrel of the syringe.

. 7. A syringe such, as. set forth in claim 1 in which the relatively large flushing channel or channels extend laterally through the neck across the interior face of the end wall of the bulb and in a direction to form an obtuse angle with respect to the longitudinal axis of the bulb and neck and in which at least one minute air passage extends through the face of the end wall, of the bulb into communication with the interior of the relatively large flushing channel or channels.

8. A syringe such as set forth in claim 1 in which the relatively large flushing channel or channels extend laterally through the neck across the interior face of the end wall of the bulb and in a direction to form an obtuse angle with respect to the longitudinal axis of the bulb and neck and in which the minute air passage or passages include a rigid tube extending through the face of the end'wall of the bulb into communication with the interior of the bulb.

9. A syringe such as set forthin claim 1 in which the relatively large flushing channel or channels extend laterally through the neck across the interior face of the end wall of the bulb and in a direction to form an obtuse angle with re-' spect to the longitudinal axis of the bulband neck and in which the minute air passage or passages include a rigid tube extending through the face of the end wall of the bulb into communication with the interior of the bulb terminating approximately flush with that face of that wall of a flushing channel which is closest to the interior of the barrel of the syringe.

10. A syringe comprising a barrel provided at one end with a nozzle and at its opposite end with an inner surface adapted to frictionally engage the exterior of the neck and end walls of a bulb, a compressible bulb having a neck and an end wall the end wall being thicker than the walls of the bulb and the neck, said thickened end wall and neck being adapted exteriorly thereof to frictionally engage said inner surface of said barrel, the air content of the bulb being substantiallyless than the liquid-containing capacity of the barrel, one or more relatively large flushing passages extending laterally through the neck, the outer open end of said passage or passages being positioned between the regions where there is complete and continuous frictional contact between the. neck and the barrel, relatively minute air passages extending through the thickened end wall of the bulb into the interior of the bulb between the interior of the barrel and the interior of the bulb, the aggregate cross-sectional dimensions of all of the air passages through the said end wall of the bulb being so limited that upon inversion of the syringe, fluid contained in the barrel will be restrained from passing into the bulb the thickened end wall of the bulb in the assembly of the bulb and barrel resisting reduction in size of the air passages less than the minimum requirements for proper expulsion of air "from the bulb through the-air passages into-the 5with' aninner surface adapted to frictionally syriiige barrel.

11. A syringe comprising a barrel provided at -one end with a nozzle and at its opposite end engage the neck of a bulb, a compressible bulb -having an end wall and a'neck adapted "exteriorly thereofto frictionally engage said inner of the ,airpa'ssage- -01" passages through the tube or tubes =being= so limited 1 that upon: inversion surface of said barrel and a relatively minute air I passage 'or passages extending through the end *wall of the bulb between the interior of the barrel and the interior of the bulb; said minute air passage or passages comprising awrigid tube I or tubes' of corrosion resisting material extending through and surrounded'iby the'compressible 'ma- "terial 'of'thee'nd wall of the bulb and. sufliciently rigid to resistreduction of the cross 'sectionof the passage er-passages through the tube or tubes.

upon I compression ofthe-compressible -materia1 of the-neck of the bulb-0n insertion of thelatter into thebarrel, the cross sectional dimensions of the syringe fluid contained in i the barrel will 

